逻辑、心理与认知——论后弗雷格时代逻辑学的发展

Logic, Mind and Cognition——On the Development of Logic in the post-Frege Time

20世纪初产生的弗雷格逻辑拒斥人和心理因素,但即使在弗雷格时代,它也仅仅是逻辑学的一种流派,同时还有重视心理因素的直觉主义逻辑和其他逻辑理论的存在。在后弗雷格时代,逻辑学实现了对自然语言和人的回归,如乔姆斯基的唯理主义和心理主义语言学在语言分析中强调先天语言能力,重视心理因素。此时,心理逻辑将逻辑分析与心理分析结合在一起,重新考虑人的因素和心理因素对人类思维的影响。在认知科学的背景下,逻辑学只有重新回归于人,才能在探索人类心智奥秘的过程中发挥应有的作用。

Frege＇s logic, which denies the factors of mankind and his mind, is just suitable in some fields, e.g. in deduction, but not in induction, of mathematics. We would be wrong if we extended his truth to other fields, for example, daily life or philosophy. Something like the factors of mankind and mental elements that Frege gave up is just the starting point of new revolution in logic and philosophy. After Frege, logicians and philosophers returned to the natural language in the middle of the 20^th century. J. L. Austin （1955） found some kinds of utterances, performatives that are of doing something in saying something, which are meaningful but not true or false. Then, he created his famous theory of speech acts, which is the foundational theory of pragmatics that gives consideration to man, the user of language. N. Chomsky （1957） developed his syntactic theory in rationalism and psychologism, which takes Language Faculty （LF） as innate, viewing language as the mirror of mind. After these developments, a new inter-discipline, cognitive science, was set up in the mid 1970s. Therefore, this author thinks that it would be necessary to institute a new frame of logic in the background of cognitive science, say, cognitive logic. The author got the cognitive logic system made up of six disciplines-philosophlcal logic, mental logic, logic of language, logics in culture and evolution, logics in AI, and logic of neuro-web-by mapping six branches of cognitive science into the fields of modern logic. The author points out that some new fields of cognitive logic, such as mental logic and logic in culture and evolution should be paid more attention to. In this paper, the different characteristics of mental logic and Frege＇s logic are analyzed in detail. Mental logic is a new discipline integrating logic with psychology, in which the mentation that Frege had forsaken came back again into logic. The author points out that logic faculty, like language faculty, is also innate. Therefore, logic must have some certain structures and modalities that are genetic, innate and mental. Finally, the author concludes that logic cannot function in exploring man＇s mind in cognitive science until it has returned to mankind himself.